In the original paper (K.B. Janiszowski, ibid., vol. 38, no. 8, p. 1313-16, 1993) there is presented a modification of the Tustin approximation. The author argues that the justification of this modification, by means of three examples, is not convincing, because the choice of the examples is questionable and some calculations are not sufficiently accurate. It is shown that some good properties of ...
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A new criterion for delay-independent stability of linear large scale time-delay systems is deduced by employing an improved Razumikhin-type theorem and the m-matrix properties. An illustrative example is given to demonstrate the superiority of the obtained results to those in the literature
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An important class of linear time-varying systems consists of plants where the state-space matrices are fixed functions of some time-varying physical parameters θ. Small gain techniques can be applied to such systems to derive robust time-invariant controllers. Yet, this approach is often overly conservative when the parameters θ undergo large variations during system operation. In gen...
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This paper is concerned with an asymptotic analysis of hierarchical production and setup scheduling in a stochastic manufacturing system consisting of a single failure-prone machine and facing constant demands for a number of products. At any given time the system can only produce one type of product, and the system requires a setup if production is to be switched from one type of product to anoth...
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Conventional spectral analysis fails in identifying systems operating with feedback from noisy input-output data. It is shown that polyspectral and cyclic methods can identify closed-loop systems with data corrupted by a class of stationary and cyclostationary noise. The class is specified and nonparametric transfer function estimators are developed and simulated
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This paper investigates the problem of finite-horizon H∞ tracking for linear time-varying systems. Three tracking problems are considered, depending on whether the reference signal is perfectly known in advance, measured on-line, or previewed in fixed interval of time ahead. No a priori knowledge of a dynamic model for the reference signal is assumed. A game theory approach to the...
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This paper presents a robust indirect adaptive stabilization controller for systems with linear time-invariant (LTI) nominal parts, uncertain dynamic errors, and bounded disturbances. The a priori knowledge required for designing the adaptive controller is that the nominal part of the system is of known order and is stabilizable
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This paper presents a simple procedure for constructing reduced-order models that match some Markov parameters and time moments of an original system as well as the energies of its impulse response and of other combinations of the system modes. In this way, the stability of the reduced model of a stable system is ensured
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It is well known that the continuation methods have been successfully applied to solve polynomial systems and fixed point problems, etc. In this paper, we consider a discrete-time algebraic Riccati equation with an admissible, low rank, and symmetric perturbation. Our attention is directed primarily to this modified discrete-time algebraic Riccati equation and the numerical method for its solution...
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This paper considers the solution of large-scale linear optimal control problems subject to linear control and state constraints by application of a linear programming (LP-) based methodology. The proposed algorithm is based on a particular LP-method that is suitably modified and adapted to the structure of the considered discrete-time dynamic problem to keep the computation time low and efficient...
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The problem under consideration is how to estimate the frequency function of a system and the associated estimation error when a set of possible model structures is given and then one of them is known to contain the true system. The “classical” solution to this problem is to, first, use a consistent model structure selection criterion to discard all but one single structure, second, es...
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The set-membership identification of systems with parametric and nonparametric uncertainty is studied. The bias induced by the additive noise is eliminated by using the bias-eliminated least squares method proposed previously by us (1991). A prefilter is connected to the input terminal of the system, so that some zeros are inserted to the system. By using the information obtained from these known ...
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Motivated by the computation of the H∞ optimal performance and optimal mixed sensitivity for a class of infinite dimensional systems, the author considers the explicit computation of the norm and minimal symbols of a class of “Hankel plus Toeplitz” type operators with irrational symbols using the Krein space approach. The author shows how to explicitly compute the norm...
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A dynamic output feedback controller for flexible joint robots is presented which guarantees asymptotic tracking of a desired trajectory, starting from arbitrary initial conditions. The controller needs only the measurements of the positions of the links and the knowledge of an upper bound on the initial tracking error
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We extend the class of control problems that can be modeled by Petri nets considering the notion of weak terminal behavior. Deterministic weak languages represent closed-loop terminal behaviors that may be enforced by nonblocking Petri net supervisors if controllable. The class of deterministic weak PN languages is not closed under the supremal controllable sublanguage operator
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This note is concerned with performance prediction of multiple-target tracking systems, particularly in data-rich, high-target-density environments. Two simple but useful expressions are described: (i) the exponential law for predicting average probability of correct data association, and (ii) the linear-times-exponential law for calculating the effective measurement error variances with possible ...
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Considers the problem of approximately feedback linearizing a multi-input nonlinear system around the equilibrium manifold &epsi; while making the error terms be of highest order on &epsi;. Necessary and sufficient conditions are given for approximately feedback linearizing the system around &epsi; with error terms of order ρ on &epsi;. A simple multi-input example is given to illustrate the h...
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In this paper, the expansion of det(A+B+C) is given. The robustness problem for discrete-time state-space systems with uncertain parameters is investigated by applying the Schur stability theory of interval polynomials. A stability robustness criterion for the uncertain systems is derived. Illustrative examples are presented
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In this note a robust periodic pole assignment algorithm is proposed for linear, time-invariant, discrete-time systems. The condition numbers of the eigenvector matrices of the closed-loop system are assumed as a robustness measure and a periodic state-feedback law is deduced by the minimization of the condition numbers associated to the eigenvectors of the monodromy matrix of the closed-loop syst...
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In this paper, global asymptotic stability of a class of nonlinear multibody flexible space structures under certain dissipative compensation is established. Furthermore, for an important subclass of such systems, the stability is shown to be robust to certain types of actuator and sensor nonlinearities. The results are applicable to robust stabilization of a wide class of systems, including flexi...
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In this paper, the (blind) identifiability of systems using the second-order output cyclic spectra is considered. It is shown that the class of minimal, stable, rational causal (MSRC) systems is not identifiable, and the identification is limited by a nontrivial ambiguity associated with the so-called cyclic all-pass factor. The largest subclass of MSRC systems that ensures the unique identificati...
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Presents some new square-root algorithms that allow more reliable computation of the state estimates, using, as far as possible, quantities obtained via orthogonal operations. New algorithms are given for covariance quantities and information quantities, and a new combined algorithm is also presented
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Hu claims new results in the above mentioned paper (ibid. vol.39, no.1, p.180-2 (1994)) regarding decentralized stabilization of large scale interconnected systems with delays. This note shows that the results presented in Theorems 1 and 2 and Corollaries 1 and 2 apply only to a very restrictive class of systems for which the number of inputs and outputs is equal to the number of states. An altern...
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Based on a decomposition of the rigid robot system with motor dynamics, a novel sliding-adaptive controller is developed which can achieve robustness to parameter variations in both manipulator and motor. When the system is in sliding mode, force, position, and redundant joint velocity errors will approach zero irrespective of parametric uncertainties. Unlike conventional sliding techniques which ...
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The matrix n-sector function is a generalization of the matrix sign function; it can be used to determine the number of eigenvalues of a matrix in a specific sector of the complex plane and to extract the eigenpairs belonging to this sector without explicitly computing the eigenvalues. It is known that Newton's method, which can be used for computing the matrix sign function, is not globally conve...
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Aims & Scope

In the IEEE Transactions on Automatic Control, the IEEE Control Systems Society publishes high-quality papers on the theory, design, and applications of control engineering. Two types of contributions are regularly considered